Diagnostic Test

1) DTC IS ACTIVE
Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes
1. Go to 2).
No
1. Refer to the *CHECKING FOR AN INTERMITTENT CONDITION Diagnostic Procedure.
2) (K99) O2 1/1 HEATER CONTROL CIRCUIT SHORTED TO VOLTAGE

Fig 1: Measuring Voltage Of (K99) O2 1/1 Heater Control Circuit In Oxygen Sensor 1/1 Harness Connector
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Oxygen Sensor 1/1 connector.

Disconnect the Powertrain Control Module (PCM) connector.

Turn the ignition on.

Measure the voltage of the (K99) O2 1/1 Heater Control circuit in the Oxygen Sensor 1/1 harness connector.

Is there any voltage present?

Yes
1. Repair the (K99) O2 1/1 Heater Control circuit for a short to voltage.
2. Perform PCM VERIFICATION TEST .
No
1. Go to 3).
3) (K99) O2 1/1 HEATER CONTROL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 2: Checking O2 Sensor 1/1 Heater Control Circuit For Open Or High Resistance
Courtesy of CHRYSLER LLC

Measure the resistance of the (K99) O2 1/1 Heater Control circuit between the Oxygen Sensor 1/1 harness connector and the Powertrain Control Module (PCM) harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Go to 4).
No
1. Repair the (K99) O2 1/1 Heater Control circuit for an open circuit or high resistance.
2. Perform PCM VERIFICATION TEST .
4) OXYGEN SENSOR 1/1

Fig 3: Checking (K99) O2 1/1 Heater Control Circuit In Oxygen Sensor 1/1 Harness Connector
Courtesy of CHRYSLER LLC

Connect the Powertrain Control Module (PCM) connector.

Turn the ignition on.

With the scan tool, actuate the Oxygen Sensor 1/1 control to the ON (100%) position.

Using a 12 volt test light connected to ground, check the (K99) O2 1/1 Heater Control circuit in the Oxygen Sensor 1/1 harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

With the scan tool, actuate the Oxygen Sensor 1/1 control to the OFF (0%) position.

Using a 12 volt test light connected to ground, check the (K99) O2 1/1 Heater Control circuit in the Oxygen Sensor 1/1 harness connector.

NOTE: The test light should not be illuminated.

Is the test light illuminated and bright with the actuator ON (100%) and not illuminated with the actuator OFF (0%)?

Yes
1. Replace the Oxygen Sensor 1/1 in accordance with the Service Information.
2. Perform PCM VERIFICATION TEST .
No
1. Go to 5).
5) POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 and the Powertrain Control Module (PCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes
1. Repair as necessary.
2. Perform PCM VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
2. Perform PCM VERIFICATION TEST .